Electromechanical variable-speed device.



H. H. CUTLER & F. S. WILHOIT. BLECTROMEGHANI-GAL VARIABLE SPEED DEVICE.

APPLIGATIOI? FILED NOV. 30, 1908.

Patented D80. 29, 1914.

3 SHEETS-SHEET 1.

I fi jje x v 17 H. H. CUTLER & F. S. WILHOIT, ELEGTBOMEOHANIGAL VARIABLE SPEED DEVICE.

APPLICATION FILED NOV. 30, 1908.

. 1 y 1 22,83. Patented Dec. 29, 1914.

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ELEGTROMEGHANIGAL VARIABLE SPEED DEVICE. APPLICATION FILED 110V. 30, 1908.

1,122,483. Patentd Dec. 29,1914.

Wail/222 4J7? "U ITED STATES.

HENRY H. CUTLER AND FREDERIC S. WILHOIT, 0F MILWAUKEE, WISCONSIN.

ELEC'I'BOMECHANICAL VARIABLE-SPEED DEVICE.

Application filed November 80, 1908. Serial No. 465,165.

To all whom, it may concern:

Be it known that we, HENRY H. CUTLER and Fnnnnmo SHELTON Wmuorr, citizens of the United States, residing at. Milwaukee,

in the county of- Milwaukee and State of Wisconsin; have invented new and useful Improvements Electromechanical Variable-Speed Devices, of which-the, following is a full, clear, concise, and exact descrip tion, reference being had'to the accompanying drawings, forming a part of this specification.

Our invention relates to improvements in magnetic clutch ower transmitting appara tus, as set forth in our,original'application,

Serial No. 215,198, filed July. 2, 1904.-

Oneobjectof our invention is toprovide miproved means whereby power may be transmitted froma suitable mechanism to the driven mechanism in an efiicient and economical manner.

A further object of our invention is to provide means for driving a. driven mechanism at several fundamental speeds, difi'ering from each other. by comparatively large increments, and a still further object is to providemeans whereby we may provide for finer radations of speed between the funda menta speeds obtained.

The referred manner in which we accomplish t e several objects of our invention is drive the machine by a motor of any standa rd ma kc and increase the speed of said motor a above the normal by shunt field resistance. In a patent granted-to Henry H. Cutler, April 5. 1905, No. 786,411, is described and claimed on improved form of magnetic clutch or accelerator, which, when usedin this device, provides aclutch in which, with the driving member operating at its maximum speed, the driven member under fullload may be started from rest and aceelerated up to synchronism with the driving member without strain or jarto the machinery.

in the drawings, in, wh-ichlike figuresire fer to like parts throughout the several fig-.

ures, Figure 1 is a plan view of our device, drawing a portion of the clutch in section; Fig. '2 is a diagrammatic view of the circuits employed in a device of this character; Fig. 3 is a face view of one of the clutch nary types.

ber's; Fig. 4 is a sectional view of a modification of the clutch; and, Fig. 5 is a sectional view of still another modification.

In the structure which we have worked out as being the preferred embodiment of our invention, the variable speed device consistsof two shafts, 1 and 2, mounted in suitable ournals with the several gears, and

magnetic clutches mounted thereon. Upon the shaft 1 and suitably keyed thereto is mounted a primary member 3 of a double magnetic clutch. The primary member 3 of the clutch is provided with two magnetic field members, and each field member is tions 7, and the ring 6 having outwardlyv extending polar projections 8, the two sets of poles being arranged in overlapping positions and held in position against the back plate 4 by bolts or screws 9.

The space between the pole pieces are filled with non-magnetic material 10, which may be Babbitt metal or other equivaalent material. An annular channel is formed in each face of the back plate, and

the two sets of rings, 5 and 6, in connection it therewith form annular channels for the recept-ion' of the annular windings 11 and 12 of the twoffield magnets. Upon the outer periphery of the back plate 4 are formed 7 gear teeth 16.

The magnetis thus so constructed that the energizing winding is entirely surrounded by iron. Consequently, when the circuit through said winding is 'completed,

the current throughthe windingand consequently the strength of the magnetic field in the inducing or primary member is retarded, due to the-large amount of induc-. tance. The strength, therefore, of the field will increase slowly and thus prevent the sudden acceleration of the driven member I of the clutch which has caused such serious objections to magnetic clutchesof the ordi- Furthermore, the arrangement of the outer and inner rings 5 and 6 rovides a field magnet, which is subdivided into a large number of individual magnetic circuits, which aid in causing a rapid disappearance of the residual magnetism in the armature member. that the magnetic flux, when the current is admitted to the energizing windings, will start from the poles, which are arran ed to have the same polarity, say, the inwar 1y extending pole pieces, and pass into the armature member, dividing into two parts which I and from the pole pieces back to the starting point. The armature member then has flux flowing in adjacent parts in opposite directions, which meet and pass down through the pole pieces without interfering as long as the magnetizing force continues. However, as soon .asthis-force'is withdrawn I by opening the circuit, the two oppositely flowing fluxes will' meet in the armature member in opposition to each other and thereby neutralize each other, causing the residual magnetism to rapidly disappear and the clutch members to instantly release. However, in a clutch of thismharacter, the time lag after current has been cut off, is great enough to make it frequently desirable to eliminate even this small lag and have the clutch release instantaneously, in which case the field magnets are constructed as shown in Figs. 4 and 5, which show a modification of the primary member of our clutch. By interposing an air gap 13 between the back plate 4 and the rings 5 and 6, which may be accomplished in any way, such as the interposition of small washers 14 between the rings, and the contact plate, .a ma net1c circuit whereby the residual magnetism will be caused to instantly disappear when the current is cut ofi from the energizing coils. Another means for accomplishing this same result is shown in Fig. 5, in which we have shown a thin layer 15 of non-magnetic material or magnetic material of lowrpcrmeability which will act in the same general manner as the air gap, causing a magnetic reluctance in the magnetic circuit and thereby insuring a quick disappearance of the residual magnetism when the current is cut off from the coils. l Ve have shown in the drawings, the air gap and-the layer of non-magnetic material as being greatly enlarged for the purpose of illustration, as in actual practice the air gap of the strip need only be one sixtyfourth of an inch in thickness, which would be sufficient thickness to eliminate the residual magnetism and yet would not be great enough to have any but a very slight efiect in decreasing the power of the clutch.

lit will be noted that during the operation of the clutch illustrated, the armature This is due to the fact etic reluctance is inserted in the magmenses in mechanical contact with the face of the field magnet member and the air gap is thus entirely eliminated and the reluctance of the magnetic circuit isreduced to a minimum. A continuous frictional surface is thus presented to the armature and, therefore, besides the inductive infiuencc of the field magnet member upon the armature member, a frictional turning effect is also given. Within the journal 17 of the shaft 1 is mounted a hollow quill 18. through which the shaft 1 passes and which forms a part of the hub 19 of the gear wheel 20. A suitable brass -bushing 21 is inserted between the quill 1S and shaft 1, to provide a wearing surface therefor, and openings '22 are formed in the quill for lubricating purposes. Upon the outer portion of the quill 18 is keyed a suitable pulley 23, which is'connected by a belt with a pulley 24;, mounted on the shaft of the motor 25 An armature member 26, which inthe present instance is of annular form, is secured to one face of a steel disk 27, the inner edge of which is secured by bolts 28 to the hub 19 of the gear wheel 20. Suitably mounted upon the opposite side of the double magnetic clutch, in the bearing 30 of the shaft/1, is a second quill 31 of the same general construction as that just described, which is a part of the hub of the gear wheel 32 and secured to said gear wheel in the same manner as the armature 26 is an armature member 33. Upon the outer end of said quill is mounted a suitable pulley 34, which is adapted to be connected in any manner with the driven mechanism.

Suitablechannels 35 are formed in the clutch member, and in the shaft 1, through which the coils 11 and 12 are connected with suitable collecting rings 36, 37 and 38, mounted upon the outer end of the shaft 1. Preferably mounted in the journals 3 and 40 of the shaft 2 are suitable quills (not shown) of the same structure as those previously described, to which are secured the gears 41 and 42, having secured thereto, as above described, armature members 43 and. 44, adapted to be respectively attracted to the primary members of a. second double clutch 45, having the same general construction as the primary member 3, and keyed to the shaft 2. The clutch has suitable energizing windings 46 and 47 formed therein,

as on the first described primary member.

Suitable collecting rings 36, 37, and 38 are mounted upon one end of the shaft 2 to which are connected conductors for conveying the current to the magnetic windings 46 and 47 of the double magnetic clutch 45. The member has also formed thereon gear teeth 49.

In Fig. 2 is shown a diagrammatic view of the circuit arran ements for a speed ehanging device of this character. The opgreases erating'lever 50 of a controller 51 rotates about a hub 52, which is electrically con-.

ed to bear upon the contact ring 58 and the starting contacts 59 to 62, which contacts are suitably connected with a resistance 63. The contact ring 58 is connected by conductor 64 with one terminal of the motor 25, the opposite terminal thereof being connected with the main 65 by conductor 66. A second brush 67 is mounted upon the lever 50 and adapted to bear upon shunt field contact ring 68, which is connected by conductor 69 with one terminal. of the shunt field winding 70, the opposite terminal thereof being connected directly tothemain 65 as indicated. The brushes 56 and 67 are electrically connected by conductor 71, and are, thefefore, connected with the positive side of the line thro h conductori53.- The contact ring 68 is divided intosections 68?,

68", 68 and 68*, and arranged between" the segments are sets 72, 73, 74 and 75; ofcontact buttons which are connected with 'segments of the ring 68 through suitable starting resistance 76, 77, 78 and 79, respectively.

The inner terminal of the clutch coils -11, 12, 46 and 47, are connected with contact se ments 80, 81, 82 and 83, respectively, t e inner terminals of the winding'll being con nected with contacts 80, by conductor 84, the inner terminal of.the winding 12 being "connected'with contact 81 'by conductor 85, the inner terminal of the winding .46 being connected with contact 82, by conductor 86, and the inner terminals of the winding 47 being connected with the contact 83 by'conductor 87, respectively. The outerterminals of the clutch coils 11 and 46 are connected to-' gether and to the main 54 by conduetor 88 through the knife switch 89,andthe outer terminals of the clutches 12 and 47 are also connected together and with the main 65. by conductor 90 through the knife switch 89. Suitable brushes 91 and 92, connected together by conductor 93, are mounted upon the lever 50, but are insulated therefrom and serve to close the circuits through the respective energizing windings.

In order to prevent the operator from stopping the lever 50 with the brushes 91 and 92 between the several contact segments and thus allow the driven machine to come to rest, the outer end of the lever is provided with a roller 94, having a suitable coil spring 95 for normally pressing the same outwardly. The roller 94 is adapted to engage rollers '96, 96, mounted upon the base upon which the controller is carried, and when the lever 50 en ages the same it will he stopped momentariy, just before the brushes 91 and 92 leave one contact ring and as the lever is moved it will then be thrown quickly to the next contact as the roller 94 passes the rollers 96, due to the action of the spring 95.

When thevlmain knife'swit'ch 55 is closed, and the lever-50 in such a position that the brush 56 bears upon the first contact 59, current may be traced from the main 54, through conductor 53 t5 the hub v52 of the lever through the conductor 57 to the brush 56, contact 59Ithrough the resistance 63 to contact ring- 58, and thence by conductor 64 through the armature 'of the "motor 25 to the opposite main 65 by conductor 66. At the same time current will. flow through the conductor 71, brush 67, contact segment 68, conductor 69 through the shunt field windin'g70, and thence to the oppo'siterside of themain 65. This starts themotor with all the'resistance 63 in seriestherewith, and as the contact arm 50 is moved in a clock-wise direction, the starting resistance'63 is graduallyfcut. out, as the brush 50 passes successively. over the"conta"ct's 59. to 62', until the'mbtor will be operating. at full normal speed on full" field strength. While .the

' brush 56 is being moved over the segments 59 to62, and'untll it'makes contact with the segment 58, the brushes 91' and -92w"'llbear upon the insulated segments 97 and none of the clutches will be energized, therefore,"

the motor. will run at its'norm'a'l speed without driving the machinery to which the same is geared. v

As the lever 50 is moved .in a clock-wise. direction the brushesv .91 and '92 v will make contact with the'rings 82 and 83,- and circuit may then be traced from the main 54 through knife switch 89 through conductor 88, energizing windings 46, conductor 86, contact ring 82, brush 91,. conductor 93, brush 92, contact ring 83, conductor 87, through the energizing windings 47, conductor'90, knife switch 89, back to the oppositemain 65'. With current passing through the energizing coils/46 and 47, the magnetic with the brush 56 resting on the contact 62,

its

which instance the motor 25 will operate the pulley 23 and the gear 20, which in turn will drive the gear 41, and through the double magnetic clutch 45,- the gear 42. The gear wheel 42 meshes with the "gear 32"and drives the same and the pulley 34.mounted on the hub thereof. -Operating inthis manner, the slowest speed at whichthe' driven machinery may be operated by the motor 25 is obtained. As the lever 50 is moved still farther in a clock-wise direction, it will successively pass over the set of contacts 72, inserting a resistance 76 in the shunt field circuit of themo tor. and thereby increasing the speedof the motor, until at the last contact ofthis series ice the motor willibe operating at its maximum speed on weakened field, but still upon the firstgear combination. As'the lever 50 is moved still farther in the clock-wise direction, the brush 67 will move oh the last of the series 'of'contacts 7 2," and;.upon the con,- tact'segment 68, thereby cutting out all shuntfield resistances and leaving the motor operating upon normal 'field strength. At

the same-time the brush 91 breaks contact with the ring .82, openin the clutch coil circuits and disconnecting e gearing from the motor momentarily, but at the'next instant the brush 91 makes, contact with the contact segment 80, thebrush 92 still-being in contactwith the segment 83 current will flow from the main 54: through the knife switch 98, through conductor 88,through the clutch windingsll, conductor 84, contact ring 80, brush 91,:conductor=93, brush 92, contact ring .-8 3, conductor 857, through: the clutch winding i47,andiby' conductor 90 and switch 89;backI to thezopposite side of the 'maini65. Withthe coils 11 and 4:7 energized, the armatures 26 and 44 will be attracted to their respective primary members, and, as the motor continues to operate, the gear will be operated by the pulley 23, said gear meshing' with the gear 41 will drive the same. 3e However, this gear being loosely mounted upon the shaft 2 will be allowed to rotate loosely thereon and not operate said shaft. Since the armature 26 has been attracted by the energized coil 11, the clutch member 3 t5: and the shaft 1 will thereby bedriven at the same speed as that at which the gear 20 is operating. Consequently, the gear 16 meshing-Avith'the gear 49 will operate the same together-with the clutch member 45 and the co shaft 2.; Since the winding 47 is energized the armature'td has been attracted, and the pinion 42 will, be driven at the same speed as the shaft 2 and will transmit its motion to the gear wheel 32 and pulley or gear Wheel {it 34:, giving a speed somewhat faster than the one previously described. To increase the speed of the driven mechanism with this combination of gears, the operating lever 50 is moved still farther in a clock-wise direction, and the brush 67 is adapted to pass over the second seriesof terminals 73, thereby inserting the resistance 77 in the shunt field circuit and increasing its speed until the motor again attains its maximum operating speed on weakened field with the brush 67 upon-the last of the series of contacts 73. Upon a further movement of the lever 50 the Y brush 67 will move 0d of the last of the series of contacts 7 3 and onto the segment 68,

6@ thereby cutting out the resistance in the shunt field circuit and the brushes 91 and 92 will'break contact with the rings .83 and and makecontact with the rings 82 and 81. With the lever in this position circuit may 95 then be traced from the mainht through mes es through the windings 46 and 12 and causes thearmatures'isjand 33 to be attracted to their respective primary members. With the armature members 43 and 33 attracted '25 to their respective primary members, the pulley 23 will operate the car 20, which in turn will drive the gear t which through the clutch 45 will operate the gear 49, transmitting motion to the gear 16, and thence by so the attracted armature member 33 to the pulley 34, which will drive the machine at its third speed. The motor will now be operating the machine at an increased speed, that is, at an increased speed through the 05 combination of gears, but the motor itself. will be operating at a normal s eed. There fore, when the lever 50 is move still farther in a clock-wise direction it will pass over the series of contacts 74:, inserting resistance 78 959 in the shunt field circuit, thereby increasing the speed of the motor untilfinally all the resistance is inthe shunt field circuit and the motor will be operatingat its highest speed. Upon a still further movement of the Q5 lever 50 the brush 67 will pass ed the last of the series of contacts 74: and onto the segments 68,cutting out the resistance in the shunt field winding and the motor will again be operating at its normal speed. At the same time the brush 91 will pass ofi contact 82 and engage contact 80 and the circuit may be traced from the main 54 through the switch 89, through conductor 88, through winding 11, through conductor 84, contact 80, brush 91, conductor 93, brush 92, contact 81, thence by conductor 85 through the windings l2, and from thence by conductor and the switch 89 to the opposite main 65. The circuit through the coils 11 and 12 I now being completed, the armatures 26 and 33 will be attracted to the primary members and the driven mechanim will be operated at the highest speed attainable through the last combination of gears, the motor driving 11116 the pulley 3d directly through the first clutch member 3. Upon a still further movement of the lever 50, the brush 67 will pass over the series of contacts 7 5, thereby insert ing the resistance 7 9 in the shunt field circuit mo and the motor will operate ,atits highest speed.

'lo'reduce the speed of the driven member from the maximum to the minimum, the operating lever 50 is simply moved backward me in a counter clock-wise direction when the various combinations hereinbefore specified will take place in just the reverse order, reducing the speed of the motor from the maximum to normal as, the shunt held as: me

area,

sistance is gradually cut out of circuit, and reducing the gear speed combination as the different combination of clutch circuits are successively made.-

If it is desired to stop the driven tool, for any reason, while operating at any speed, it is simply necessary to open the switch 89 which opens the clutch circuits, demagnetizing the clutches that at the time are energized, and releasing the driven tool from the motor. The motor continues to operate on no load until the switch 89 is again closed when the driven tool is again connected to the motor through the clutch and gear equipment. If the tool, while driven at any particular speed, has been stopped by'openmg the knife switch 89, the controller lever 50 may be 'moved to such position as will result in the tool being driven at a faster or slower speed, as desired, beforethe switch 89 is again closed.

With the equipment as described above, it

is possible to start the driving motorup v we have on from rest to its normal speed without load upon the'same, and then connect the driven tool to themotor by means of the magnetic clutches and gears,'beginning with the minimum ear speed combination and then grad-' ually lncreasing the speed of the driven tool to its-maximum without having to stop the motor'or tool while making the chan es in speed. It'is also possible to start an stop the tool without the'necessity of the o' erator moving the controlling lever, and w ile y shown one switch for accomplishing this result, it will be understood that if the driven mechanism is of very-large proportion, a number of stopping switches can be located at the convenient oints aboutthe device, 'from either of whic the oper-' ator can start and stop without having to go to the controller,

While" we have shown,as the preferred arrangement of connection for a device of this character, the two-clutch; coils which are energized'at the same time for any given speed combination connected across the has in series, it'will be understood that we also contemplate to have the four-clutch coils, each connected directly across the line for the different speed combinationa- We have merely shown this one way, as for some reasons it is desirable, as, for instance, the coils can-be wound with coarser wire, butit Wlll be understood that various other arrangements may be made withoutdeparting: from the spirit of our invention. I

By the use of the magnetic clutch set forth we are enabled to change from one speed combination to another without strain 7 u on the motor or upon the numerous are. The gradual acceleration of s eed pro need by said clutch permits the riven part to come u to s eed without the consequent jars an shoe so noticeable in most machines of this character, and by the provision of the clutch the diflerentiparts release instantly when a change is made from one combination of gears to another, and the arts do not pull against one another as won (1 be the case if the released parts were not disconnectedimmediately.

It will be understood that while the rimary members are shown and describe as being the center members of the clutches, we

- driven member to be operated at any one of a predetermined number of speeds, said clutch devices being adapted to act independently of one another to produce certain speed variations and te a'ct conjointly to pro-v duce" other speed variations. 1

2, In a variable speed mechanism,incombination, a driving member and} a driven member and a. plurality of electromagnetic clutch devices for operativel'y connecting said members to cause said driven'member to be operated at-anyone of a predetermined number of speeds, said clutch'devices being adapted to act independently of one another to produce certain speed variations and to act conjointl to produce other speed variations, said 0 utch devices having their corresponding membersoperatively connected together.

3. In a variable speed mechanism,'in combination, a driving member and a driven member and a plurality of electromagnetic clutch devices for operatively connecting said members to cause said driven member to; be operated at any one of a predetermined number of speeds adapted to act independently of one another to produce certain s eed variations'and toact conjointlyto pro uce other speed variations, one of said clutch devices having certain of itsm'emberso eratiVeI connected to) v said drivin and driven mem ers and each.

oi. its mem rs geared to' the corresponding member of the other clutch. device. 4 In a variable speed mechanism, in combination, a driving member, a driven member, a -gear'connected to the driving'member,

said clutch devices being another gear meshing therewith, a ear 'coni nected to the driven member anot er gear meshin therewith and two electromagnetic clutch evices having simultaneousl revoluble parts and other parts connects to said gears, said clutch devices being adapted to be operated to cause said driving member to operate said driven member at any one of a number of speeds equal to the number of said gears.

.5. In a variable speed mechanism, in combination, a driving member, a driven member, a gear operatively connected to each of said members, an electromagnetic clutch device having two of its members provided with gears each meshing with one of said first mentioned gears, a second electromag- Y netic clutch device having two members each gage either of said relatively movable members, the corresponding members of said clutches being connected, r

7. In a variable speed mechanism, in com bination, a pair of simultaneously revoluble shafts arranged substantially parallel to one another, a pair of transmitting wheels loosely mounted on each' of said shafts, and clutches for causing either or both of the transmitting-wheels on each shaft to revolve therewith. V

8. In a variable speed mechanism, in combination, a pair of simultaneously revoluble shafts arranged substantially parallel to one another, a pair of transmitting wheels loosely mounted upon each of said shafts, said transmitting wheels having different speed ratios, and magnetic clutches for causing either or both of the transmitting wheels on each shaft to rotate therewith.

9. In a variable speed mechanism, in combination, a pair of simultaneously revoluble shafts arranged substantially parallel to one other, a pair of transmitting wheels loosely mounted on each of said shafts, said transmitting wheels having diflerent speed ratios adriv ng member connected to one of sai transmitting wheels, a driven member connected to another of said transmitting wheels, electromagnetic clutches for causing either or both of the transmitting wheels on each shaft to rotate therewith, and means meshes for energizing the windings of said clutches in a definite sequence to gradually increase the speed of said driven member.

10. In a variable speed mechanism, .in combination, a pair of simultaneously revoluble shafts arranged substantially parallel to one another, a driving vmember and a driven member loosely mounted on one of said shafts, each of said members being provided with a gear wheel, a pair of gear wheels loosely mounted on the other of said shafts and arranged to mesh with said first mentioned gear wheels, said gear wheels having different speed ratios, and clutches for causingeither or both of the ear wheels on each shaft to revolve therewit 11. In a variable speed mechanism, in combination, a pair of simultaneously revoluble shafts arranged substantially parallel to one another, a driving member and ,a driven member loosely mounted on one of said shafts, each of said members bein provided with a gear .wheel, a pair 0 wheels loosely mounted on the other of said shafts and arranged to mesh with said first mentioned gear wheels, said gear wheels having-different speed ratios, and a double magnetic clutch secured to each of said shafts, said'clutches being adapted to cause either or both of the'gear wheels on-each shaft to. revolve therewith.

12. In a variable speed mechanism, in combination, a pair of simultaneously rev oluble shafts arranged substantially parallel to one another, a driving member and a driven member loosely mounted on one of said shafts, each of said members bein provided with a gear wheel, a pair 0 gear wheels loosely mounted on the other of said shafts and arranged to mesh with said firstmentioned gear wheels, said gear wheels having difierent speed ratios, a double magnetic clutch secured to each of said shafts, said clutches being adapted to cause either or both of the gear wheels'on each shaft to revolve therewith, and means for energizing the windings of said clutches in a definite sequence to gradually increase the speed of said driven member.

In witness whereof, we have hereunto subscribed our names in the presence of two witnesses.

.Witnesses:

S. W. lFrrzGrnnann, lFnAnn II. Hnnaaan.

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